26.4 Snapshot 1 adds a dedicated network packet so servers can see exactly what mods clients are running. It's a small technical change that could save server owners hours of debugging headaches.
If you run a modded Minecraft server you know the drill. Player joins, something breaks, and you spend the next hour asking what mods they have installed, which versions, whether they match the server pack, and if they forgot to remove that one random performance mod. Mojang just made that conversation shorter.
In 26.4 Snapshot 1 they added a new custom packet payload called minecraft:mod_list. Servers can now automatically receive a list of the mods running on the connecting client. The stated goal is simplifying debugging. It is hard to argue with that.
Other notable changes
- Old worlds upgraded from pre-Caves and Cliffs now generate sulfur caves in those chunks
- Red and brown mushrooms can be placed on any solid top face regardless of light level
- Vulkan is now the default graphics API on supported systems
- New dedicated server property allowed-connection-ids to filter incoming connections by ID
- Data pack version bumped to 122, resource pack to 98
- Fixed the annoying bug where players auto-jump when pressing against blocks in water
The snapshot is live in the launcher for anyone who wants to test it. Most players will not notice the mod_list packet but server admins and modpack creators will. Expect it to become standard in popular modded server software quickly.
The next update cycle is officially underway after the Wilderness Bound drop. Whether 26.4 brings new content or stays mostly technical remains to be seen but the foundation for better modded multiplayer tooling is already here.